Food casings, especially artificial sausage casings which comprise substances which can be transferred to the food or the sausage meat emulsion are already known. For instance, WO 98/31731 and EP-A 986 957 disclose films which, on the side facing the food, have a layer which comprises a flavor or aroma component and also a polysaccharide or protein as binder. The support layer of the films consists of polyolefin, polyamide, polyester, poly(vinylidene chloride) (PVDC), poly(vinyl chloride) (PVC) or polystyrene.
JP-A 139401/2000 describes a film by which food color can be transferred to sausage meat emulsion, ham or similar foods. This is achieved by a coating which, in addition to the food dye, also contains an edible plasticizer, such as glycerol, sorbitol or propylene glycol.
EP-A 992 194 (=DE-A 198 46 305) relates to a barrier casing made of a synthetic material, the casing being coated on the inside with a layer of an absorbent material which is impregnated with dyes or aroma substances (woven fabric, knitwear or knitted fabric). During cooking or scalding, the dyes or aroma substances are transferred to the food enclosed by the casing. The inner layer is bonded to the adjacent layer of the casing generally by an adhesive. The barrier casing itself consists, for example, of polyamide and polyethylene layers. It is generally produced from a corresponding flat film by heat sealing or gluing, and ensures mechanical stability. A great disadvantage of this casing is that it cannot be taken off completely, i.e. parts of the inner layer remain on the food. The reason is considered to be an insufficiently mechanically stable bond between the plastic material and the textile inner layer.
Cellulose-based tubular food casings are already described which, on the side facing the food, carry smoke aroma and/or spices. These casings have a high permeability to water vapor and oxygen. A food situated in the casing therefore dries out relatively quickly and can only be kept for a short time.
All the known casings having inner layers or inner coatings which comprise a transferrable food additive usually have the disadvantage that either their production is technically very complex, that they cannot transfer the food additives in a sufficient amount, or that they are in part difficult to remove.